Spiral excitation assembly of prefilled automatic injection pen and prefilled automatic injection pen

Abstract

A spiral excitation assembly of a prefilled automatic injection pen and a prefilled automatic injection pen comprising the spiral excitation assembly. The spiral excitation assembly of the prefilled automatic injection pen comprises: a cavity (6) for changing a rotary motion of a threaded push rod (5) into an axial forward movement; a nut (9), which is capable of being rotatably mounted in the cavity (6) relative to the cavity (6), with a torsion spring (7) capable of driving the nut (9) to rotate being arranged between the nut (9) and the cavity (6); the threaded push rod (5), which is in threaded connection with the interior of the nut (9) and driven by the rotation of the nut (9) to move forward and then drive a prefilled syringe (4) to move to complete automatic needle insertion; a clutch member (10), which is sleeved outside the nut (9) and capable of being driven by an excitation sleeve (3) of the prefilled automatic injection pen to move from an engaged position to an excitation position, wherein the clutch member engages with the nut (9) to stop the nut (9) when in the engaged position, and the nut (9) can rotate when the clutch member is in the excitation position; and a clutch spring (8), which is mounted between the clutch member (10) and an end cover (11) and is used for driving the clutch member (10) from the excitation position into a limiting position to limit backward movement of the excitation sleeve (3) to achieve needle protection post-injection, and to cause the clutch member (10) to collide with the nut (9) to produce a sound.

Description

A spiral excitation component of a prefilled automatic injection pen and a prefilled automatic injection pen Technical Field

[0001] The present invention belongs to the technical field of automatic injection, and in particular relates to a spiral excitation component of a prefilled automatic injection pen and the prefilled automatic injection pen. Background Art

[0002] The pre-filled auto-injection pens currently on the market have the following disadvantages:

[0003] 1. To achieve automatic injection, these products currently use electric motors as the power source for the injection mechanism. This approach consumes energy, is costly, and requires a complex control system. The use of batteries also contributes to environmental pollution. Connecting these devices to various transmission mechanisms also results in a bulky product, making them difficult to port and easy to use.

[0004] 2. To achieve multi-dimensional feedback, most products on the market rely on electronic components for visual and auditory feedback, and these products still require battery power. This can lead to product failure when used in environments with strong electromagnetic interference. Electronic components are susceptible to environmental influences and aging, making them unsuitable for long-term storage. This makes it difficult to ensure the stability and reliability of the entire device when used in complex environments.

[0005] 3. Currently, such products on the market have many operating steps, often requiring at least three steps. Patients still face the risk of forgetting when using them periodically, and patient compliance is poor.

[0006] 4. Currently, after use, products on the market often require the user to insert a stop pin or rotate a locking mechanism to self-lock the product, thereby preventing secondary use and accidental activation. However, in certain situations, the stop pin may be lost or the patient may forget to operate it, making it impossible for the product to ensure self-locking after use. This design violates ergonomics and is not in line with the design characteristics of this type of product.

[0007] 5. In order to achieve the automatic injection function, most existing products use structural designs such as snap-on designs on the trigger mechanism, using the elastic deformation of the parts to complete the triggering and locking processes. This design often requires the snap-on structures and other structures to be in a compressed and deformed state. Since such products are disposable, the parts are usually injection molded from polymer materials. The compression of the snap-on structure of the parts is not conducive to transportation and long-term storage, and is greatly affected by the environment. Such structures are prone to plastic deformation. Summary of the Invention

[0008] In response to the problems described in the above background technology, the purpose of the present invention is to provide a spiral activation assembly and a prefilled automatic injection pen that are reliable in activation, have a reliable injection completion reminder function, and can achieve needle protection.

[0009] The technical solution adopted in the present invention is:

[0010] A spiral excitation component of a pre-filled automatic injection pen, comprising

[0011] The cavity is fixed to the housing of the prefilled automatic injection pen and is used to convert the rotational motion of the threaded push rod into axial forward motion;

[0012] A nut is rotatably mounted in the cavity, and a torsion spring is provided between the nut and the cavity to drive the nut to rotate.

[0013] A threaded push rod, which is threadedly connected to the nut and driven forward by the rotation of the nut, then drives the pre-filled syringe to move and complete automatic needle insertion;

[0014] The clutch is mounted on the outside of the nut and can be moved from the engaged position to the activated position under the drive of the activation sleeve of the pre-filled automatic injection pen. When in the engaged position, it engages with the nut to stop the nut. When in the activated position, the nut can rotate;

[0015] an end cap which is fitted onto and detachably connected to the rear end of the nut;

[0016] The clutch spring is installed between the clutch and the end cover. It is used to drive the clutch from the excitation position to the limiting position after the injection is completed to limit the excitation sleeve from moving backward to protect the needle, and to make the clutch collide with the nut to produce a sound. After excitation, the present invention drives the threaded push rod forward by rotating the nut to drive the pre-filled syringe to move and complete automatic needle insertion. Compared with the form of a spring-driven push rod, it is more reliable. At the same time, the clutch is combined to achieve excitation and needle protection. Compared with elastic deformation to complete the triggering, locking and other processes, the excitation and needle protection are more reliable. In addition, the clutch cooperates with the nut to produce an injection sound. The structure is simpler and more reasonable, and the cooperation is smoother.

[0017] Furthermore, the clutch member is a hollow cylindrical structure, and lugs are symmetrically protruded on its surface for driving or limiting in cooperation with the excitation sleeve.

[0018] Furthermore, a first chute for the lug to move from the engaged position to the excitation position and a second chute for the lug to move from the excitation position to the restraining position are formed between the front end face of the end cap and the rear end face of the cavity. The first chute is connected to the second chute, and the lug protrudes out of the first and second chute. The lug of the present invention is in constant contact with the excitation sleeve during the process of moving from the engaged position to the excitation position.

[0019] Furthermore, a right-angled trapezoidal groove that is wider on the outside and narrower on the inside is symmetrically formed on the front end surface of the end cap, and an oblique W-shaped groove is symmetrically formed on the rear end surface of the cavity. The width of the opening end of the right-angled trapezoidal groove is smaller than the width of the opening end of the oblique W-shaped groove. The oblique directions of the right-angled trapezoidal groove and the oblique W-shaped groove are consistent, and a first chute and a second chute are formed between the right-angled trapezoidal groove and the oblique W-shaped groove. In the present invention, since the width of the opening end of the right-angled trapezoidal groove is smaller than the width of the opening end of the oblique W-shaped groove, when the lug moves from the excitation position along the second chute to the limiting position, the lug is limited at the limiting position, thereby limiting the backward movement of the excitation sleeve.

[0020] Furthermore, meshing teeth are provided on the front end face of the clutch and the end face of the middle part of the nut. When in the meshing position, the meshing teeth on the clutch and the meshing teeth on the nut engage and stop. When entering the limited position, the meshing teeth on the clutch and the meshing teeth on the nut can collide and make a sound.

[0021] Furthermore, the nut includes a nut body with a hollow cylindrical structure, and the interior of the nut body is provided with an internal thread that cooperates with the threaded push rod for threaded driving.

[0022] Furthermore, a cover with an opening facing forward is provided in the middle of the nut body, a cavity for accommodating a torsion spring is formed between the cover and the nut body, and the meshing teeth on the nut are provided on the rear end surface of the cover.

[0023] Furthermore, a convex rib is provided on the surface of the cover body, a groove is provided on the cavity relative to the convex rib, and the convex rib is located in the groove to axially limit the nut.

[0024] Furthermore, an L-shaped positioning groove is provided at the rear end of the nut body, and a positioning piece is protruded from the interior of the end cover and is detachably connected to the positioning groove.

[0025] Furthermore, the front end surface of the cavity is flatly matched with the threaded push rod, thereby limiting the threaded push rod from rotating and only allowing it to move axially.

[0026] A spiral-activated prefilled automatic injection pen comprising

[0027] a housing, which is a hollow structure;

[0028] A protective cap, which is fastened to the head of the shell and can cause the inner protective rubber sleeve of the prefilled syringe to fall off together when it is pulled out;

[0029] An excitation sleeve is movably mounted in the housing and is provided with a return spring axially between the housing and the housing for resetting. The head of the excitation sleeve is exposed outside the housing and can trigger the spiral excitation assembly when it moves from an initial position to an extreme position.

[0030] The prefilled syringe is clamped on the PFS seat when pre-filled. When the activation sleeve moves from the initial position to the extreme position, the injection end of the prefilled syringe is always hidden in the needle sheath. When the injection end of the prefilled syringe is triggered, it moves instantly and extends the activation sleeve to realize automatic needle insertion.

[0031] The PFS seat is fixedly installed between the ignition sleeve and the prefilled syringe, and initially defines the initial position of the prefilled syringe and provides support when the prefilled syringe is automatically inserted;

[0032] The spiral excitation component of the pre-filled automatic injection pen is installed in the shell.

[0033] Furthermore, the excitation sleeve includes a sleeve body for protecting the needle, the sleeve body is provided with a symmetrical extension arm, and the tail end of the extension arm is provided with an excitation portion for cooperating with the lug for excitation and a limiting portion for cooperating with the lug for limiting.

[0034] Compared with the prior art, the present invention has the following significant advantages:

[0035] 1. After being excited, the spiral excitation assembly drives the threaded push rod forward by rotating the nut to drive the pre-filled syringe to move and complete automatic needle insertion. It is more reliable than the spring-driven push rod.

[0036] 2. The clutch is combined to achieve excitation and needle protection. Compared with elastic deformation to complete the triggering and locking processes, the excitation and needle protection are more reliable. In addition, the clutch cooperates with the nut to produce injection sound, which is simpler and more reasonable in structure and smoother in coordination. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is a schematic diagram of the explosion structure of the spiral excitation assembly of the present invention;

[0038] FIG2 is a schematic structural diagram of the cavity of the spiral excitation assembly of the present invention;

[0039] FIG3 is a schematic structural diagram of a nut of a spiral excitation assembly of the present invention;

[0040] FIG4 is a schematic structural diagram of a clutch member of a spiral excitation assembly of the present invention;

[0041] FIG5 is a schematic structural diagram of the end cap of the spiral excitation assembly of the present invention;

[0042] FIG6 is a schematic cross-sectional view of the clutch member of the spiral excitation assembly of the present invention when it is in the engaged position;

[0043] 7 is a schematic cross-sectional view of the clutch member of the spiral excitation assembly of the present invention when it is in the excitation position;

[0044] FIG8 is a schematic cross-sectional view of the clutch member of the spiral excitation assembly of the present invention when it is in a limited position;

[0045] FIG9 is a schematic diagram of the structure of the spiral excitation assembly of the present invention cooperating with the excitation sleeve in the initial state;

[0046] FIG10 is a schematic structural diagram of the spiral excitation assembly of the present invention for needle protection after excitation.

[0047] FIG11 is a schematic diagram of the exploded structure of the prefilled automatic injection pen of the present invention;

[0048] FIG12 is a schematic diagram of the appearance structure of the pre-filled automatic injection pen of the present invention;

[0049] 13 is a schematic structural diagram of the excitation sleeve of the pre-filled automatic injection pen of the present invention;

[0050] FIG14 is a schematic cross-sectional view of the clutch member of the prefilled automatic injection pen of the present invention when it is in the engaged position;

[0051] 15 is a schematic cross-sectional view of the clutch member of the pre-filled automatic injection pen of the present invention when it is in the activation position;

[0052] FIG16 is a schematic cross-sectional view of the clutch member of the prefilled automatic injection pen of the present invention when it is in a limited position.

[0053] Among them, 1. protective cap, 1a, protective cap buckle, 2. shell, 21, visual window, 3. excitation sleeve, 31, sleeve body, 32, extension arm, 33, excitation part, 34, limiting part, 35, slot, 36, protective buckle, 4, pre-filled syringe, 41, internal protective rubber sleeve, 42, protruding tail end, 5, threaded push rod, 6, cavity, 61, oblique W-shaped groove, 62, groove, 7, torsion spring, 8, clutch spring, 9, nut, 91. Nut body, 92. Cover, 93. Concave cavity, 94. Raised rib, 95. Positioning groove, 10. Clutch, 101. Lug, A. Engaging position, B. Excitation position, C. Limiting position, 11. End cover, 111. Right-angled trapezoidal groove, 112. Positioning piece, 12. PFS seat, 121. Cantilever, 122. External buckle, 123. Internal buckle, 124. Step surface, 13. Engaging teeth, 14. First slide groove, 15. Second slide groove. DETAILED DESCRIPTION

[0054] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all possible alternatives, improvements and equivalents within the scope of the claims.

[0055] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more, unless otherwise clearly defined.

[0056] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0057] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0058] Example 1

[0059] 1-10, this embodiment provides a spiral excitation assembly for a pre-filled automatic injection pen, comprising

[0060] The cavity 6 is fixed to the housing 2 of the prefilled automatic injection pen and is used to convert the rotational motion of the threaded push rod 5 into axial forward movement;

[0061] The nut 9 is rotatably mounted in the cavity 6, and a torsion spring 7 is provided between the nut 9 and the cavity 6 to drive the nut 9 to rotate.

[0062] The threaded push rod 5 is threadedly connected to the nut 9 and is driven forward by the rotation of the nut 9 to drive the pre-filled syringe 4 to move and complete the automatic needle insertion;

[0063] The clutch member 10 is mounted on the outside of the nut 9 and can be moved from the meshing position A to the ignition position B under the drive of the ignition sleeve 3 of the pre-filled automatic injection pen. When in the meshing position A, the clutch member 10 engages with the nut 9 and stops the nut 9. When in the ignition position B, the nut 9 can rotate;

[0064] An end cap 11 is mounted on and detachably connected to the rear end of the nut 9;

[0065] The clutch spring 8 is installed between the clutch 10 and the end cover 11. It is used to drive the clutch 10 from the excitation position B to the limiting position C after the injection is completed to limit the excitation sleeve 3 from moving backward to protect the needle, and to make the clutch 10 collide with the nut 9 to produce a sound. After excitation, the present invention drives the threaded push rod 5 forward by rotating the nut 9 to drive the prefilled syringe 4 to move and complete the automatic needle insertion. Compared with the form of a spring-driven push rod, it is more reliable. At the same time, the clutch 10 is combined to achieve excitation and needle protection. Compared with elastic deformation to complete the triggering, locking and other processes, the excitation and needle protection are more reliable. In addition, the clutch 10 also cooperates with the nut 9 to produce injection sound, which is simpler and more reasonable in structure and smoother in cooperation.

[0066] The clutch member 10 of this embodiment is a hollow cylindrical structure, with symmetrically protruding lugs 101 on its surface for driving or limiting the activation sleeve 3. A first chute 14 for the lug 101 to move from the engagement position A to the activation position B and a second chute 15 for the lug 101 to move from the activation position B to the limiting position C are formed between the front end face of the end cap 11 and the rear end face of the cavity 6. The first chute 14 and the second chute 15 are connected, and the lug 101 protrudes from the first chute 14 and the second chute 15. The lug 101 of the present invention remains in contact with the activation sleeve 3 during the movement from the engagement position A to the activation position B. Specifically, a right-angled trapezoidal groove 111 that is wide on the outside and narrow on the inside is symmetrically provided on the front end surface of the end cover 11, and an oblique W-shaped groove 61 is symmetrically provided on the rear end surface of the cavity 6. The width of the opening end of the right-angled trapezoidal groove 111 is smaller than the width of the opening end of the oblique W-shaped groove 61. The oblique directions of the right-angled trapezoidal groove 111 and the oblique W-shaped groove 61 are consistent, and a first slide groove 14 and a second slide groove 15 are formed between the right-angled trapezoidal groove 111 and the oblique W-shaped groove 61. In the present invention, since the width of the opening end of the right-angled trapezoidal groove 111 is smaller than the width of the opening end of the oblique W-shaped groove 61, when the lug 101 enters the limiting position C from the excitation position B along the second slide groove 15, the lug 101 is limited at the limiting position C, thereby limiting the backward movement of the excitation sleeve 3. The first slide groove 14 and the second slide groove 15 are formed by the end cover 11 and the cavity 6 to facilitate the loading and unloading of the clutch 10. Of course, the first sliding groove 14 and the second sliding groove 15 can be directly provided on one of the components.

[0067] In this embodiment, the front end surface of the clutch member 10 and the middle end surface of the nut 9 are both provided with meshing teeth 13. When in the meshing position A, the meshing teeth 13 on the clutch member 10 engage with the meshing teeth 13 on the nut 9 to stop the clutch. When in the restricted position C, the meshing teeth 13 on the clutch member 10 and the meshing teeth 13 on the nut 9 collide and produce a sound. The meshing teeth 13 on the nut 9 are arranged continuously, while the meshing teeth 13 on the clutch member 10 are arranged at intervals.

[0068] The nut 9 described in this embodiment includes a nut body 91 with a hollow cylindrical structure. The interior of the nut body 91 is provided with an internal thread that cooperates with the threaded push rod 5 for threaded drive. A cover body 92 with an opening facing forward is provided in the middle of the nut body 91. A concave cavity 93 for accommodating the torsion spring 7 is formed between the cover body 92 and the nut body 91. The engaging teeth 13 on the nut 9 are provided on the rear end face of the cover body 92. A rib 94 is provided on the surface of the cover body 92. A groove 62 is provided around the position of the cavity 6 relative to the rib 94. The rib 94 is located in the groove 62 to axially limit the nut 9 so that the nut 9 can only rotate relative to the cavity 6. An L-shaped positioning groove 95 is provided at the rear end of the nut body 91. A positioning member 112 is provided on the inside of the end cover 11 to be detachably connected to the positioning groove 95.

[0069] The front end surface of the cavity 6 described in this embodiment is flatly matched with the threaded push rod 5, that is, the through hole at the front end of the cavity 6 is a flat hole, and the threaded push rod 5 is a flat structure with an external thread on its arc surface, thereby limiting the rotation of the threaded push rod 5 and allowing it to move axially only.

[0070] Initially, the clutch 10 is engaged with the nut 9, preventing the threaded push rod 5 from being pushed. During use, when the activating sleeve 3 moves axially, its activating portion 33 contacts the lug 101 of the clutch 10, driving the lug 101 from the engaged position A to the activating position B, thereby disengaging the clutch 10. At this point, the nut 9, driven by the torsion spring 7, rotates, thereby driving the threaded push rod 5. Constrained by the cavity 6, the threaded push rod 5's rotation is converted into axial forward movement, thereby activating the prefilled syringe of the prefilled autoinjector pen to move and automatically insert the needle. After the injection is completed, the excitation sleeve 3 rebounds, and its excitation part leaves the lug 101. Under the action of the clutch spring 8, the lug 101 moves from the excitation position B to the limiting position C. At this time, the lug 101 contacts the limiting part 34 of the excitation sleeve 3, thereby preventing the excitation sleeve 3 from moving axially backward again, thereby realizing needle protection and causing the meshing teeth 13 of the clutch 10 to collide with the meshing teeth 13 of the nut 9 to make a sound.

[0071] After activation, the present invention drives the threaded push rod 5 forward through rotation of the nut 9, thereby driving the prefilled syringe to move and automatically insert the needle. This is more reliable than a spring-driven push rod. Incorporating a clutch 10 to achieve activation and needle protection is more reliable than elastic deformation to complete triggering and locking processes. Furthermore, the clutch 10 also cooperates with the nut 9 to produce the injection sound, resulting in a simpler and more reasonable structure and smoother coordination.

[0072] Example 2

[0073] Referring to Figures 11-16, this embodiment provides a spiral-activated prefilled automatic injection pen, including a protective cap 1, a shell 2, an activation sleeve 3, a prefilled syringe 4, a threaded push rod 5, a cavity 6, a torsion spring 7, a clutch spring 9, a nut 10, a clutch 10, an end cover 11, and a PFS seat 12, wherein the threaded push rod 5, the cavity 6, the torsion spring 7, the clutch spring 9, the nut 10, the clutch 10, and the end cover 11 constitute a spiral activation assembly, which is installed in the shell 2.

[0074] The protective cap 1 of this embodiment snaps onto the head of the housing 2 and, when removed, removes the internal protective rubber sheath 41 of the prefilled syringe 4. Specifically, the protective cap 1 is provided with symmetrically arranged protective cap buckles 1a, which initially engage with the internal protective rubber sheath 41 of the prefilled syringe 4. When the protective cap 1 is removed, the internal protective rubber sheath 41 of the prefilled syringe 4 detaches from the prefilled syringe 4, exposing the needle tip.

[0075] The housing 2 of this embodiment is a hollow structure. The housing 2 is provided with a visual window 21 for checking the status of the drug solution, whether the pre-filled syringe is positioned correctly, and for checking the infusion status after registration is completed.

[0076] The excitation sleeve 3 described in this embodiment is movably installed in the housing 2 and is provided with a return spring for reset axially between the housing 2. The head of the excitation sleeve 3 is exposed outside the housing 2. When it moves from the initial position to the extreme position, it can trigger the spiral excitation assembly. Specifically, the excitation sleeve 3 includes a sleeve body 31 for protecting the needle tip. The sleeve body 31 is provided with a symmetrical extension arm 32. The tail end of the extension arm 32 is provided with an excitation portion 33 that cooperates with the lug 101 on the clutch 10 for excitation and a limiting portion 34 that cooperates with the lug 101 to limit. The extension arm 32 is provided with a slot 35 for the cantilever 121 of the PFS seat 12 to move. The inner side of the extension arm 32 is provided with a protective buckle 36 at one end of the slot 35 that radially protrudes to limit the initial position of the cantilever 121 of the PFS seat 12.

[0077] The prefilled syringe 4 described in this embodiment is clamped on the PFS seat 12 when pre-installed. During the process of the excitation sleeve 3 moving from the initial position to the extreme position, the injection end of the prefilled syringe 4 is always hidden in the needle sheath. When the injection end of the prefilled syringe 4 is triggered, it is displaced instantly and the excitation sleeve 3 is extended to realize automatic needle insertion. Specifically, the prefilled syringe 4 is clamped at the position of the cantilever 121 on the PFS seat 12 when pre-installed. This position is the initial position of the prefilled syringe 4. When excited, the excitation sleeve 3 moves from the initial position to the extreme position. When the excitation sleeve 3 is at the extreme position, the injection end of the prefilled syringe 4 is hidden in the excitation sleeve 3. When the injection end of the prefilled syringe 4 is triggered, it is displaced instantly, moving from the initial position to the step surface 124 on the PFS seat 12, and exceeding the excitation sleeve 3 to realize automatic needle insertion; the injection end is a needle structure, and is initially provided with an internal protective rubber sleeve 41 to protect the injection end; the prefilled syringe 4 is pre-filled with liquid and sealed by a rubber plug; the protruding tail end 42 of the prefilled syringe 4 is protruding, which can be limited to the initial position by the PFS seat 12, and cooperate with the step surface 124 on the PFS seat 12 to limit the moving distance.

[0078] The threaded push rod 5 described in this embodiment is threadedly connected to the nut 9 and is driven forward by the rotation of the nut 9, which then drives the pre-filled syringe 4 to move and complete automatic needle insertion; the threaded push rod 5 is a flat structure, and an external thread is provided on its arc surface, which rotates in conjunction with the internal thread in the nut 9.

[0079] The cavity 6 described in this embodiment is a hollow structure fixed to the housing 2 and used to convert the rotational motion of the threaded push rod 5 into axial forward movement. Specifically, the front end surface of the cavity 6 is flatly aligned with the threaded push rod 5, that is, the through hole at the front end of the cavity 6 is a flat hole, thereby restricting the threaded push rod 5 from rotation and only allowing axial movement. A groove 62 is provided within the cavity 6 relative to the position of the rib 94 of the nut 9. The rib 94 is located within the groove 62, axially limiting the nut 9 to rotation relative to the cavity 6.

[0080] The clutch spring 8 described in this embodiment is installed between the clutch member 10 and the end cover 11, and is used to drive the clutch member 10 from the excitation position B to the limiting position C after the injection is completed to limit the excitation sleeve 3 from moving backward to protect the needle, and to cause the clutch member 10 to collide with the nut 9 to produce a sound.

[0081] The nut 9 of this embodiment is rotatably mounted within the cavity 6, with a torsion spring 7 disposed between the nut and the cavity 6 to drive the nut 9 in rotation. The nut 9 comprises a hollow cylindrical nut body 91, internally threaded with an internal thread that engages with the threaded push rod 5. A cover 92, opening forward, is positioned around the center of the nut body 91. A cavity 93 is formed between the cover 92 and the nut body 91 to accommodate the torsion spring 7. The meshing teeth 13 of the nut 9 are located on the rear end of the cover 92. A rib 94 is formed around the surface of the cover 92, which axially retains the nut 9 within the groove 62, ensuring that the nut 9 can only rotate relative to the cavity 6. The rear end of the nut body 91 includes an L-shaped positioning groove 95 for connecting and securing the end cap 11. After activation, the present invention drives the threaded push rod 5 forward through rotation of the nut 9, thereby driving the prefilled syringe to automatically insert the needle, making it more reliable than a spring-driven push rod.

[0082] The clutch 10 described in this embodiment is mounted on the outside of the nut 9 and can be moved from the meshing position A to the excitation position B under the drive of the excitation sleeve 3. When in the meshing position A, it engages with the nut 9 to stop the nut 9. When in the excitation position B, the nut 9 can rotate. Specifically, the clutch 10 is a hollow cylindrical structure, and its surface is symmetrically protruded with lugs 101 that cooperate with the excitation sleeve 3 to drive or limit. The front end face of the clutch 10 and the end face of the middle part of the nut 9 are both provided with meshing teeth 13. When in the meshing position A, the meshing teeth 13 on the clutch 10 engage and stop with the meshing teeth 13 on the nut 9. When entering the limiting position C, the meshing teeth 13 on the clutch 10 and the meshing teeth 13 on the nut 9 can collide and make a sound. The meshing teeth 13 on the nut 9 are continuously arranged, and the meshing teeth 13 on the clutch 10 are arranged at intervals. At the same time, the clutch 10 is combined to achieve excitation and needle protection. Compared with elastic deformation to complete the triggering, locking and other processes, the excitation and needle protection are more reliable, and the clutch 10 also cooperates with the nut 9 to produce injection sound, which is simpler and more reasonable in structure and smoother in cooperation.

[0083] The end cap 11 of this embodiment is fitted onto and detachably connected to the rear end of the nut 9; a positioning member 112 protrudes from the interior of the end cap 11 and is detachably connected to the positioning groove 95. A first chute 14 for the lug 101 to move from the engagement position A to the excitation position B and a second chute 15 for the lug 101 to move from the excitation position B to the limiting position C are formed between the front end face of the end cap 11 and the rear end face of the cavity 6. The first chute 14 is connected to the second chute 15, and the lug 101 protrudes from the first chute 14 and the second chute 15. The lug 101 of the present invention remains in contact with the excitation sleeve 3 during the movement from the engagement position A to the excitation position B. Specifically, a right-angled trapezoidal groove 111 that is wide on the outside and narrow on the inside is symmetrically provided on the front end surface of the end cover 11, and an oblique W-shaped groove 61 is symmetrically provided on the rear end surface of the cavity 6. The width of the opening end of the right-angled trapezoidal groove 111 is smaller than the width of the opening end of the oblique W-shaped groove 61. The oblique directions of the right-angled trapezoidal groove 111 and the oblique W-shaped groove 61 are consistent, and a first slide groove 14 and a second slide groove 15 are formed between the right-angled trapezoidal groove 111 and the oblique W-shaped groove 61. In the present invention, since the width of the opening end of the right-angled trapezoidal groove 111 is smaller than the width of the opening end of the oblique W-shaped groove 61, when the lug 101 enters the limiting position C from the excitation position B along the second slide groove 15, the lug 101 is limited at the limiting position C, thereby limiting the backward movement of the excitation sleeve 3. The first slide groove 14 and the second slide groove 15 are formed by the end cover 11 and the cavity 6 to facilitate the loading and unloading of the clutch 10. Of course, the first sliding groove 14 and the second sliding groove 15 can be directly provided on one of the components.

[0084] The PFS seat 12 described in this embodiment is fixedly installed between the excitation sleeve 3 and the prefilled syringe 4, and initially limits the initial position of the prefilled syringe 4 and can provide support when the prefilled syringe 4 is automatically inserted; the PFS seat 12 is symmetrically provided with a cantilever 121, and the cantilever 121 is provided corresponding to the slot 35 of the excitation sleeve 3, and the outer side of the end of the cantilever 121 is provided with an outer buckle 122 which initially cooperates with the protective buckle 36 of the excitation sleeve 3 to limit the position of the cantilever 121, and the inner side of the end of the cantilever 121 is provided with an inner buckle 123 which initially cooperates with the protruding tail end 42 of the prefilled syringe 4 to support the prefilled syringe 4; the inner wall of the PFS seat 12 is provided with a step surface 124 for limiting the movement of the prefilled syringe 4, and the inner wall of the PFS seat 12 is axially provided with a vertical rib position from the step surface 124 to its tail end to provide support for the prefilled syringe 4 when the needle is automatically inserted. After the outer buckle 122 of the cantilever 121 of the PFS seat 12 is released from the protective buckle 36, the cantilever 121 can be deformed within the slot 35, so that the prefilled syringe 4 is pushed open by the threaded push rod 5 to move downward to the stepped surface 124. A silicone gasket can be provided on the stepped surface 124 to protect the protruding tail end 42 of the prefilled syringe 4 and prevent it from breaking during movement.

[0085] When installing the spiral excitation assembly of the present invention, the threaded push rod 5 is installed on the nut 9 to form a nut assembly, the nut assembly and the torsion spring 7 are installed in the cavity 6, and a ring connection is achieved through the rib 94 and the groove 62; the clutch part 10 and the clutch spring 8 are sequentially mounted on the outside of the nut 9, and finally the end cover 11 is fixed to the rear end of the nut 9.

[0086] When installing the front portion of the prefilled automatic injection pen, the return spring is installed into the trigger sleeve 3, which is then installed into the housing 2. The protective cap 1 is then installed into the housing 2 and covers the trigger sleeve 3. The PFS holder 12 is then installed into the housing 2 and positioned in conjunction with the trigger sleeve 3. The cantilever 121 on the PFS holder 12 is now positioned within the slot 35 of the trigger sleeve 3, with the outer buckle 122 and protective buckle 36 cooperating for initial positioning. The prefilled syringe 4 is then installed into the PFS holder 12, with the inner buckle 123 cooperating with the protruding tail end 42 to limit the position. Finally, the assembled spiral trigger assembly is installed into the housing 2 and secured to the housing 2 via the cavity 6.

[0087] At the beginning of the present invention, the clutch 10 is engaged with the nut 9, and the threaded push rod 5 cannot be pushed. When the present invention is used, the protective cap 1 is pulled off to separate the internal protective rubber sleeve 41 from the prefilled syringe 4. The excitation sleeve 3 is pressed down, and the excitation sleeve 3 moves backward. When the excitation portion 33 of the excitation sleeve 3 contacts the lug 101 of the clutch 10, the lug 101 is driven to move from the engaged position A to the excitation position B, thereby driving the clutch 10 to leave the engaged position. At this time, the nut 9 rotates under the drive of the torsion spring 7, thereby driving the threaded push rod 5 to rotate. Under the restriction of the cavity 6, the threaded push rod 5 is converted from rotation to axial movement forward, thereby stimulating the prefilled syringe of the prefilled automatic injection pen to move and automatically insert the needle. After the injection is completed, the excitation sleeve 3 rebounds, and its excitation part 33 leaves the lug 101. Under the action of the clutch spring 8, the lug 101 moves from the excitation position B to the limiting position C. At this time, the lug 101 contacts the limiting part 34 of the excitation sleeve 3, thereby preventing the excitation sleeve 3 from moving axially backward again, thereby realizing needle protection and causing the meshing teeth 13 of the clutch 10 to collide with the meshing teeth 13 of the nut 9 to make a sound.

[0088] After activation, the present invention drives the threaded push rod 5 forward through rotation of the nut 9, thereby driving the prefilled syringe to move and automatically insert the needle. This is more reliable than a spring-driven push rod. Incorporating a clutch 10 to achieve activation and needle protection is more reliable than elastic deformation to complete triggering and locking processes. Furthermore, the clutch 10 also cooperates with the nut 9 to produce the injection sound, resulting in a simpler and more reasonable structure and smoother coordination.

Claims

1. A spiral excitation assembly for a prefilled automatic injection pen, characterized in that: include A cavity (6) fixed to the housing (2) and used to convert the rotational motion of the threaded push rod (5) into axial forward motion; A nut (9) is mounted in the cavity (6) so as to be rotatable relative to the cavity (6), and a torsion spring (7) is provided between the nut and the cavity (6) to drive the nut (9) to rotate; A threaded push rod (5) is threadedly connected to a nut (9) and driven forward by the rotation of the nut (9) to drive the prefilled syringe (4) to move and complete automatic needle insertion; A clutch member (10) is sleeved outside the nut (9) and can be moved from an engagement position (A) to an excitation position (B) under the drive of an excitation sleeve (3). When in the engagement position (A), the clutch member (10) engages with the nut (9) to stop the nut (9). When in the excitation position (B), the nut (9) can rotate. An end cover (11) is mounted on and detachably connected to the rear end of the nut (9); A clutch spring (8) is installed between the clutch member (10) and the end cover (9) and is used to drive the clutch member (10) from the excitation position (B) to the limiting position (C) after the injection is completed to limit the excitation sleeve (3) from moving backward to protect the needle and to make the clutch member (10) collide with the nut (9) to produce a sound.

2. The spiral excitation assembly of a prefilled automatic injection pen according to claim 1, characterized in that: The clutch member (10) is a hollow cylindrical structure, and lugs (101) are symmetrically protruded on its surface for driving or limiting in cooperation with the excitation sleeve (3).

3. The spiral excitation assembly of a prefilled automatic injection pen according to claim 2, characterized in that: A first slide groove (14) for the lug (101) to move from the engagement position (A) to the excitation position (B) and a second slide groove (15) for the lug to move from the excitation position (B) to the limiting position (C) are formed between the front end surface of the end cover (11) and the rear end surface of the cavity (6); the first slide groove (14) is connected to the second slide groove (15), and the lug (101) protrudes out of the first slide groove (14) and the second slide groove (15).

4. The spiral excitation assembly of a prefilled automatic injection pen according to claim 3, characterized in that: A right-angled trapezoidal groove (111) which is wide outside and narrow inside is symmetrically provided on the front end surface of the end cover (11), and an oblique W-shaped groove (61) is symmetrically provided on the rear end surface of the cavity (6). The width of the opening end of the right-angled trapezoidal groove (111) is smaller than the width of the opening end of the oblique W-shaped groove (61). The oblique directions of the right-angled trapezoidal groove (111) and the oblique W-shaped groove (61) are consistent. A first slide groove (14) and a second slide groove (15) which are connected are formed between the right-angled trapezoidal groove (111) and the oblique W-shaped groove (61).

5. The spiral excitation assembly of a prefilled automatic injection pen according to claim 1, characterized in that: The front end surface of the clutch (10) and the end surface of the middle part of the nut (9) are both provided with meshing teeth (13). When in the meshing position (A), the meshing teeth (13) on the clutch (10) and the meshing teeth (13) on the nut (9) are meshed and stopped. When entering the limiting position (C), the meshing teeth (13) on the clutch (10) and the meshing teeth (13) on the nut (9) can collide and make a sound.

6. The spiral excitation assembly of a prefilled automatic injection pen according to claim 1, characterized in that: The nut (9) comprises a nut body (91) of a hollow cylindrical structure, the interior of the nut body (91) is provided with an internal thread for threaded driving in cooperation with a threaded push rod (5), a cover body (92) with an opening facing forward is provided in the middle of the nut body (91), a concave cavity (93) for accommodating a torsion spring (7) is formed between the cover body (92) and the nut body (91), and the meshing teeth (13) on the nut (9) are provided on the rear end surface of the cover body (92).

7. A spiral excitation assembly for a prefilled automatic injection pen according to claim 6, characterized in that the surface of the cover body (92) is provided with a convex rib (94), the cavity (6) is provided with a groove (62) relative to the position of the convex rib (94), and the convex rib (94) is located in the groove (62) to axially limit the nut (9).

8. The spiral excitation assembly of a prefilled automatic injection pen according to claim 6, characterized in that: An L-shaped positioning groove (95) is provided at the rear end of the nut body (91), and a positioning piece (112) is protruded from the inside of the end cover (11) and is detachably connected to the positioning groove (95).

9. The spiral excitation assembly of a prefilled automatic injection pen according to claim 1, characterized in that: The front end surface of the cavity (6) is flatly matched with the threaded push rod (5).

10. A spiral-activated prefilled automatic injection pen comprising A housing (2) which is a hollow structure; A protective cap (1) which is snapped onto the head of the housing (2) and can drive the inner protective rubber sleeve (41) of the prefilled syringe (4) to fall off together when the protective cap is removed; An excitation sleeve (3) is movably mounted in the housing (2) and is provided with a return spring for resetting along the axial direction between the housing (2). The head of the excitation sleeve (3) is exposed outside the housing (2). When the excitation sleeve (3) moves from an initial position to an extreme position, it can trigger the spiral excitation component. The prefilled syringe (4) is clamped on the PFS seat (12) when pre-installed. When the activation sleeve (3) moves from the initial position to the extreme position, the injection end of the prefilled syringe (4) is always hidden in the needle sheath. When the injection end of the prefilled syringe (4) is triggered, it moves instantly and extends out of the activation sleeve (3) to achieve automatic needle insertion. A PFS seat (12) is fixedly installed between the excitation sleeve (3) and the prefilled syringe (4), and initially defines the initial position of the prefilled syringe (4) and can provide support when the prefilled syringe (4) is automatically inserted; Features: The housing (2) contains a spiral excitation assembly for a prefilled automatic injection pen according to any one of claims 1 to 9.

11. A spiral-activated prefilled automatic injection pen according to claim 10, characterized in that: The excitation sleeve (3) comprises a sleeve body (31) for protecting the needle, the sleeve body (31) is provided with a symmetrical extension arm (32), and the tail end of the extension arm (32) is provided with an excitation portion (33) for cooperating with the lug (101) for excitation and a limiting portion (34) for cooperating with the lug (101) for limiting.

Images